Electromagnetic sound reproducer



Jan.11,1927. 1 613,715,

c. D. WHITE ELECTROMAGNETIC SOUND REPRGDUCER Filed July 15, 1926 s Sheets-Sheet 1 132 4 4g 40 I: E- l IN V EN TOR.

+ A tw /93$ Whi Jan 11 1927. ,775

- C. D. WHITE ELECTROMAGNBTI C SOUND REPRODUGER Filed July 15, 1926 3 Sheets-Sheet 2 IN V EN TOR.

1,613,775 Jan. 11 1927. r D. WHITE ELECTROMAGNETIC SOUND REPRODUCER Filed July 15, 1926 I5 Sheets-Sheet 5 F; 5 III-21i- BY .Y 8 I 7 I Y 'ATTORNE Patented Jan; 11, 1927.

UNITED STATES PATENT OFFICE.

CHARLES D. WHITE, OF EAST OBANGR NEW JERSEY, LSSIGNOR TO BEAN DES LABORA- TOBIES, INC., OF NEWARK, NEW JEB SEY, A CORPORATION OF NEW JERSEY.

ELECTROMAGNETIC SOUND BEPRODUCEB.

Application filed July 15,

My invention relatesbroadlyto electromagnetic sound reproducers and more particularly to an electromagnetic sound repro- (lucer of the conediaphragm type.

One of the objects of my invention is to provide a construction of cone speaker which is capable of reproducing radio broadcast signaling energy at large volume and with pleasing 'tone quality.

Another object of my invention is to pro-- vide a simplified construction of'cone speaker having a direct acting conical diaphragm actuated by an electromagnetic driver in which a sound amplifying chamber is provided at the rear of the conical diaphragm for the reproduction of notes over the entire musical scale without distortion.

Another object of my invention'is to provide an inexpensive construction of cone speaker wherein the reproduction of sound from the conical diaphragm depends upon the amplification of-the sound by a sound amplifying chamber in which the diaphragm is housed with means for accurately adjust-- ing the magnetic gap between the pole tips of the electromagnetic driving mechanism and the armature from which connection is made to the reproducing conical diaphragm.

Another object of my invention is to provide a construction of cone speakers in which a bowl shaped sound amplifying chamber is provided directly adjacent the conical sound reproducing diaphragm, the bowl shaped sound amplifying chamber enclosing an area substantially larger than the area enclosed by the conical shaped diaphragm whereby musical notes reproduced by the operation of said diaphragm are amplified by the sound reproducing chamber.

Still another object of my invention is to provide'an inexpensive construction of cone speaker in which a. single casting forms the sole means of support for asound amplifying chamber, and an electromagnetic driving mechanism centrally positioned within the chamber to which a conical shaped diaphragm is connected and to which sound vibrations are imparted by the electromagnetic driving mechanism.

Other and further objects of my invention reside in the construction and arrangement of parts in the electromagnetic sound reproducer by which the manufacture-and production of cone speakers may be facilitated, as will be more fully described in the following 1926. Sci'ial Ro. 122,638.

specification by reference to the ac ompany. ing drawings in which: 7 v

Figure 1 is a verticalcross-sectional view taken through the cone speaker of my invention illustrating the electromagnetic opersiting mechanism in side elevation; Fig. 2 is a view looking toward the rear of the electromagnetic driving mechanism within the cone speaker on line 2-2 of Fig. 1; Fig. 3 is a detailed cross-sectional view of the electromagnetic'driving mechanism and adjustable control mechanism therefor; Fig. 4 is a front view of the electromagnetlc driving mechanism showing the means which are provided for supporting the sound reproducing diaphragm from the housing of the electromagnetic operating mechanism; and Fig.

5 is a cross-sectional view taken through the electromagnetic driving mechanism on line 5--5 of Fig. 4.

My invention is directed to that class of cone speakers depending for their operation upon a sound amplifying chamber in which the conical sound reproducing diaphragm is housed in accordance with the principles set forth in copending application for Letters Patent, Serial Number 60,128, filed October 2, 1925 by Cyril A. Brigham and David H. Moss. I provide, however, a. construction of cone speaker, which is considerably simplified over the constructions heretofore employed and the expense in manufacture and production considerably reduced. The embodiment of my invention, however, has

reason of the cooperation of the bowl shaped sound amplifying chamber with the conical shaped sound reproducing diaphragm for eflicientl-y reproducing musical notes over the entire musical scale.

Referring to the drawings in more detail reference character 1 designates a casting which forms the base for the cone speaker of my invention. The casting has a .vertically extending portion 2 bent at an angle as indicated at 3 with a substantially circular portion 4 at its upper extremity for housing the electromagnetic operating mechanism. The casting is provided with lug members 5, 6 and 7 extending from the sides thereof and cast integral therewith. These lug members serve as attachment means for the angularly shaped arms 8, 9 andlO on the extremities of which a retaining rim 11 is clamped within which the conical shaped edge of the sound reproducing iap sound reproducing diaphragm 12 is arranged to float. The conical shaped sound reproducing diaphragm 12 is flexibly connected to the rim 11 by means of the annular strip represented at 14 which is attached to the peripheral edge of the coneshaped sound reproducing diaphragm at 15. The strip members 8, 9 and 10 are so shaped as represented at 16 that they clear the eripheral iragm and the movement of the annular rim member 14 so that the conical shaped diaphragm 12 is free to vibrate without restriction. The apex of the conical shaped diaphragm 12 has a connecting member 17 connecting thereto through a screw collet chuck meclr anism 18 whereby mechanical vibrations from the electro-magnet.c driving mechanism which is housed within the circular casting 4 may be imparted to the round reproducing diaphragm 12.

The circular casting 4 is apertu-red as represented at 19 with annular abutment 20 formed therearound against which an armature member 21 is seated and locked in position by means of the locking ring 22 screw threaded in the internal screw threads 23 formed in the circular housing 4. An electromagnetic operating mechanism is supported from a screw threaded plate 24 which may be adjusted in the internal screw threads 23 for advancing or retracting the electromagnets 25 with respect to the armature 21 for selecting a proper magnetic gap for the reproduction of signaling energy of a particular characteristic. The electromagnetic operating mechanism includes the electromagnets 25, polev pieces 26 and permanent magnets 27 mounted from the plate 24. A sprin 28 is arranged between the plate 24 and t e locking ring 22 for preventing undesired noises from the mechanical parts of the driver during operation of the apparatus.

Y I prefer to employ a construction of armature 21 as described more particularly in Letters Patent No. 1,588,545 granted to lVilliam H. Gerns, June 15, 1926. The armature may be mounted in a variety of ways, particularly as set forth in Letters Patent 1,526,626 dated February 17, 1925 granted to Cecil E. Brigham.

Leads are brought out from the electromagnetic driving inechanism as represented at the terminals 29 and flexible connections 30 extend therefrom passing to the exterior of the apparatus. The housing which is formed around the conical shaped. diaphragm comprises a bowl shaped member 31 having an annular flange32 around its periphery cut away adjacent the base 1 as represented at 33 to form a bracket for the support of the bowl shaped member from the base 1 by any suitable means, such as securing screws 34. The bowl shaped amplifying chamber is braced adjacent its top 36 by means of a bracket member terminating at 37 on the lug 5. The front of the sound amplifying chamber is closed by means ofan annular face plate 38 snit ably ornamented for improving the esflhetic appearance of the speaker. The face plate 38 is centrally apertured as repressented at 39 and is provided with an annular flange 40 with a beaded edge 41 which fits over the raw edge of the annular flange 32 of the bowl shaped back 31 with an annular gasket 42 therebetween. This gasket 42 may be of cork or resilient material to prevent inherent metallic noises on large volumes. The face plate 38 is supported with respect to the bowl shaped back 31 .by means of screw devices 43 which pass through the flanges 40, 32 and gasket 42 at a plurality of points around the periphery of the bowl shaped amplifying chamber 31. In order to adjust the position of the electromagnetic operating mechanism with respect to the driving armature a pinion 44 is keyed to a shaft member 45 which is journaled in the lug member 5 and secured therein by means of a spring device 46 which engages the cut away portion 47 of the operating shaft 45 in the manner of a yoke. The pinion 44 meshes with teeth 48 formed on the annular rim of the, plate 24 whereby rotation of pinion 44 serves to move the electromagnetic operating mechanism to a selected position with respect to the armature 21. The locking ring 22 may be adjusted to permit the assembly and adjustment of the armature member 21 in that position for maximum operating efiiciency. In order to revent abutment of the pole pieces 26 against the armature 21 I provide a limiting stop device 49 which extends radially from the center of the rotatable plate 24 and limits the movement of the electromagnetic operating mechanism in the ,direction of the armature 21 by reason of obstruction formed by the operating shaft 25 in the path of the member 49. A complete turn of the electromagnetic operating mechanism is therefore limited by the engagement of member 49 with opposite sides of operating shaft 45. The flexible conducting cord 30 is looped through an aperture in the limiting stop 49 for preventing entanglement of the conductors with parts of the loud speaking mechanism. The operating shaft 45 passes out of the sound amplifying chamber through a bushing 50 provided in the wall of the bowl shaped back 31 and terminates, in a control knob 51 by which the electromagnetic operating mechanism may be rotated for securing the desired adjustment.

It will be observed that the construction of the cone speaker lends itself to quantity production and manufacture by reason of which the parts driver mounted on said support, a conical shaped sound reproducing diaphragm arranged to be actuated by said electromagnetic driver and a bowl shaped sound amplifying chamber surrounding said conical shaped diaphragm whereby said diaphragm operates in substantially confined air within said sound amplifying chamber for the reproduction of musical notes over I a broad range of frequencies.

2. An electroma netic sound reproducer comprising in combination a casting form ing a supporting member, an electromagnetic driving mechanism carried by said casting, a conical shaped sound reproducing diaphragm actuated by said electromagnetic driving merhanism and a bowl shaped sound amplifyin chamber carried by said supporting mem er adjacent said conical shaped sound reproducing diaphra m for the amplification of sound delivered y said diaphragm.

3. An electromagnetic sound reproducing apparatus comprising a supporting base having a vertically extending integral member, a circular housing carried by the extremity of said verticall extending member, an electromagnetic riving mechanism supported within said circular housing, a conical shaped sound reproducing diaphragm, and a sound amplifying chamber supported from said vertically extending integral member enclosing said electromagnetic operating mechanism and one side of said conical shaped sound reproducing diaphragm whereby sound delivered by said conical shaped sound reproducing diaphragm is amplified by said chamber.

4. An electromagnetic sound'reproducing apparatus comprising a basemember having a vertical extension thereon, an electromagnetic operating mechanism carried by the extremity of said vertical extension, a conital shaped sound reproducing diaphragm actuated by said electron'iaglnetic operating mechanism, and a bowl shaped sound amplifying chamber supported from said vertical extension and surrounding said conical shaped sound reproducing diaphragm for amplifying sound delivered by said diaphragm.

5. An electromagnetic sound reproducer comprising a supporting base having a substantiall vertical extension therefrom, a cirrular rousing carried on the extremity of said vertical extension, an electromagnetic driving mechanism supported within said housing, said driving mechanism including an armature and an electromagnetic operating mechanism, a conical shaped sound reproducing diaphragm, a connection between the apex of said conical shaped diaphragm and said armature, a sound amplifying chamber supported 'from said base and mains extending extcriorly of said sound amplifying chamber for adjusting the positon of said electromagnetic (nierating ICC-lb anism with respect to said armature whereby sound delivered by said conical shaped sound reproducing diaphragm may be substantially amplified by said sound amplifying chamber. I

(3. An electromagnet sound reproducer comprising a base member, a vertical mcmher extending from said base member, an electromagnetic driving mechanism carried by said vertical member, a conical shaped sound reproducing diaphragm connected to said electromagnetic driving mechanism and a pa r of closure members fitt'ng on opposite sides of said vertical member and forming a sound amplifying chamber around said conical shaped sound reproducing diaphragm whereby the sound delivered by said diaphragm is amplified.

7. An electromagnetic sound reproducer comprising a base member, a vertical member extending from said base member, an electromagnetic driving mechanism carried by said vertical member, a conical shaped sound reproducing diaphragm actuated by said electromagnetic driving mechanism, a bowl shaped closure member supported from said base member adjacent one side of said conical shaped sound reproducing diaphragm and an annular plate encircling the opposite side of said conical shaped sound reproducing diaphragm and supported from the periperal edge of said aforementioned bowl shaped closure and forming a sound amplifying chamber around said conical shaped sound reproducing diaphragm whereby sound delivered by said. diaphragm is increased in amplitude.

8. An electromagnetic sound reproducer comprising a base member, a vertical member extending from said base member, an electromagnetic driving mechanism carried by said vertical member, a conical shaped sound reproducing diaphragm actuated by said electromagnetic driving mechanism, a bowl shaped closure member supported by said base member adjacent one side of said conical shaped sound reproducing diaphragm and an annular face plate secured to the peripheral edge of said bowl shaped closure member through which said conical shaped sound reproducing diaphragm is arranged extension, a conical shaped sound reproducing diaphragm actuated by said electromagnetic driving mechamsm and a sound amplifying chamber comprising. a pair of sections telescopically fitting around said conical' shaped sound reproducing diaphragm with said conical shaped sound reproducing diaphragm projecting through one of said sections for the amplification of sound delivered by said conical shaped sound reproducing diaphragm.

10. An electromagnetic sound reproducer comprising a base member, a vertical extension on said base member, an electromagnetic driving mechanism carried by said vertical extension, a conical shaped sound reproducing diaphragm actuated by said electromagnetic driving mechanism and a sound amplifying chamber comprising a pair of circular closure members each having a diameter substantially larger than the diameter of said conical shaped sound reproducing diaphragm with saidconical shaped sound reproducing diaphragm projecting through one of said-closure members, said closure members being secured together at their peripheralvedges for forming a sound amp11-.

lying chamber around said conical shaped sound reproducing diaphra m for the amplification of sound deliverer by said conical shaped sound reproducing diaphragm.

11. An electromagnetic sound reproducer comprising a base member, a vertical member extending from said base member, an electromagnetic driving mechanism carri'ed by said vertical member, a conical shaped sound reproducing diaphragm actuated by said electromagnetic driving mechanism and a sound amplifying chamber supported, from said base member, said sound amplifying'chamber'having a diameter larger than the largest diameter of said conical shaped sound reproducing diaphragm whereby sound de- I livered by said sound reproducing diaphragmis amplified by said chamber.

In testimony whereof I afiix my' signature.

CHARLES D. WHITE. 

